I don't quite understand the hostility here... I personally like to use a flip-flop hub with a smaller free cog and a larger fixed cog (42-14 free, 42-17 fixed for me but you will find your own combos depending on terrain). It's nice to be able to coast down long hills and cruise on the flats (even if this is technically not pure "fixie") and have a larger fixed gear for getting up long hills and false flats. Don't pack an ounce more than you have to, and keep most your gear in your panniers so you can easily remove them to flip the wheel to change gears. If you don't already have them, invest in some clipless pedals as the added efficiency will help you power the bike over some of the steeper hill crests and use a more efficient stroke while cruising.

The bike I ride is a Bianchi, San Jose. The longest leg I've taken it on loaded was 77 miles along the Virginia shore of the Potomac with rolling hills but no sustained climbs, I really did not suffer any worse than my variable geared compatriots and in fact had a great time; however, I was a bit more miserly in the camp comforts I brought along to keep over all weight down.